We think you have liked this presentation. If you wish to download it, please recommend it to your friends in any social system. Share buttons are a little bit lower. Thank you!
Presentation is loading. Please wait.
Published bySelena Dice
Modified over 2 years ago
© 2012 Delmar, Cengage Learning Chapter 16 Gas Tungsten Arc Welding of Plate
© 2012 Delmar, Cengage Learning Objectives Name the applications for which the gas tungsten arc welding process is more commonly used Discuss the effects on the weld of varying torch angles Explain why the filler rod end must be kept inside the protective zone of the shielding gas and how to accomplish this Tell how tungsten contamination occurs and what should be done when it happens
© 2012 Delmar, Cengage Learning Objectives (cont'd.) Explain what can cause the actual welding amperage to change Determine the correct machine settings for the minimum and maximum welding current for the machine used, the types and sizes of tungsten, and the metal types and thicknesses List factors that affect the gas preflow and postflow times required to protect the tungsten and the weld
© 2012 Delmar, Cengage Learning Objectives (cont'd.) Determine the minimum and maximum gas flow settings for each nozzle size, tungsten size, and amperage setting Compare the characteristics of low carbon and mild steels, stainless steel, and aluminum in respect to GTA welding Describe the metal preparation needed before GTA welding
© 2012 Delmar, Cengage Learning Objectives (cont'd.) Demonstrate how to properly make GTA welds in butt joints, lap joints, and tee joints in all positions that can pass the specified standard
© 2012 Delmar, Cengage Learning Introduction Gas tungsten arc welding –Also called GTA welding –Can be used to for nearly all types and thicknesses of metal –Fluxless, slagless, and smokeless –Welders have fine control of the welding process –Used when appearance is important –Setup of equipment affects weld quality Charts give correct settings Field conditions affect the variables
© 2012 Delmar, Cengage Learning Torch Angle Key points –Torch should be held as close to perpendicular as possible –May be angled zero to fifteen degrees from perpendicular for better visibility –As the gas flows out it must form a protective zone around the weld –Too much tilt distorts protective shielding gas zone –Velocity of shielding gas affects protective zone as torch angle changes
© 2012 Delmar, Cengage Learning Filler Rod Manipulation Filler rod must be kept inside the protective zone –If removed from the gas protection Oxidizes rapidly: oxide is added to weld pool Rod tip becomes oxidized: cut it off Weld is temporarily stopped –Shielding gas must be kept flowing Rod should enter shielding gas as close to base metal as possible –Angles under 15 degrees prevent air from being pulled in welding zone
© 2012 Delmar, Cengage Learning FIGURE 16-2 The hot filler rod end is well within the protective gas envelope. Larry Jeffus
© 2012 Delmar, Cengage Learning FIGURE 16-5 Filler being remelted as the weld is continued. Larry Jeffus
© 2012 Delmar, Cengage Learning Tungsten Contamination Most frequent problem –Tungsten becomes contaminated if it touches molten weld pool or filler metal –Surface tension pulls contamination up onto the hot tungsten –Extreme heat causes some of the metal to vaporize and form a large oxide layer
© 2012 Delmar, Cengage Learning FIGURE 16-8 Contaminated tungsten. Larry Jeffus
© 2012 Delmar, Cengage Learning Tungsten Contamination (cont'd.) Contamination forms a weak weld –Weld and tungsten must be cleaned before any more welding can be done –Tiny tungsten particles will show up if the weld is X- rayed –Contamination can be knocked off quickly by flipping the torch head
© 2012 Delmar, Cengage Learning FIGURE 16-8 Contaminated tungsten. Larry Jeffus
© 2012 Delmar, Cengage Learning Current Setting Amperage on machine's control is the same at the arc when: –Power to machine is exactly correct –Lead length is very short –All cable connections are perfect –Arc length is exactly right –Remote current control is in full on position
© 2012 Delmar, Cengage Learning Experiments Designed to help new welders learn basic skills –Help troubleshoot welding problems Learn more –Subtle changes will become more noticeable –Even experienced welders make changes
© 2012 Delmar, Cengage Learning Figure Melting first occurring. Larry Jeffus
© 2012 Delmar, Cengage Learning Gas Flow Gas preflow and postflow times depend upon: –Wind or draft speed –Nozzle size –Tungsten size –Amperage –Joint design –Welding position –Type of metal welded Maximum flow rates must never be exceeded
© 2012 Delmar, Cengage Learning Practice Welds Grouped according to weld position and type of joint –Mild steel Inexpensive Requires the least amount of cleaning –Aluminum Cleanliness is a critical factor –Try each weld with each metal Determine which metal will be easier to master
© 2012 Delmar, Cengage Learning Low Carbon and Mild Steels Two basic steel classifications –Most common –During manufacturing small pockets of primary carbon dioxide gas become trapped Do not affect strength –Porosity: likely when not using a filler metal –Most filler metals have some alloys (i.e., deoxidizers) Prevent porosity caused by gases trapped in base metal
© 2012 Delmar, Cengage Learning Stainless Steel Setup and manipulation –Nearly the same as for low carbon and mild steels Welds show effects of contamination –Precleaning is important Most common problem –Bead color after the weld Using a low arc current with faster travel speeds is important –Carbide precipitation
© 2012 Delmar, Cengage Learning Aluminum Molten aluminum weld pool –High surface tension Preheat base metal in thick sections –Preheat temperature is around 300 degrees Fahrenheit Cleaning and keeping the metal clean –Time consuming Aluminum resists oxidation at room temperature –Rapidly oxidizes at welding temperatures
© 2012 Delmar, Cengage Learning FIGURE Aluminum filler being correctly added to the molten weld pool. Larry Jeffus
© 2012 Delmar, Cengage Learning Metal Preparation Base and filler metals –Must be thoroughly cleaned –Contamination will be deposited into the weld Oxides, oil, and dirt are the most common Contaminants can be removed mechanically or chemically
© 2012 Delmar, Cengage Learning Summary Position yourself to control the electrode filler metal and to see the joint –Experienced welders realize they need to see only the leading edge of the weld pool Good idea to gradually reduce your need for seeing 100% of the weld pool –Increasing this skill is significant advantage Welding in the field –May have to be done out of position
© 2012 Delmar, Cengage Learning Chapter 8 Plasma Arc Cutting.
2 © 2012 Delmar, Cengage Learning Chapter 3 Shielded Metal Arc Welding, Setup, and Operation.
© 2012 Delmar, Cengage Learning Chapter 30 Oxyfuel Welding and Cutting Equipment, Setup, and Operation.
WELDING Group D: Tarang Valecha Dhananjay R. Apurva Mali Prateek Singh.
Presentation : IMS – Tech Managers ConferenceAuthor : IMS StaffCreation date : 08 March 2012Classification : D3Conservation :Page : # 04 – ConveyorsAuthor.
Dental Film and Processing Radiographs Chapter 39 Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.
Building Foundations Concrete as a Building Material.
Introduction to HVAC Systems Presented by AirTight University.
Copyright © 2014 Delmar, Cengage Learning Thermodynamics Instructor Name: (Your Name) 3 CHAPTER.
Arc Welding Basics. 2 Unit Topics Topics included in this overview are: –Introduction What is Arc Welding? Why is Welding Important? Why Learn to Weld?
Power Tools & Equipment Chapter 4. Compressed Air Systems Air Compressor- A machine by which outside air is drawn in, compressed into a tank or cylinder,
X-ray Tube -2 Line focus principle Heal effect Ratings Tube failure.
MCG Employee Solder Training Course. Session I Agenda Coarse Objectives Terms and Definitions Soldering Tools and Materials Lead Preparation Soldering.
1 - BasM Injection Molding & Advanced Process Control SPE Automotive TPO Global Conference 2009.
Tennessee Small Business Environmental Assistance Program (SBEAP) 9 Metal Fabrication & Finishing for Small Businesses SBEAP offers free, non-regulatory.
Refrigeration Basics 101 By: Eric Nelson. Basics Refrigeration is the removal of heat from a material or space, so that its temperature is lower than.
Industrial Bearings Market in India :Issues and problems Ajay K Gupta Managing Director Kamtech Associates Pvt Ltd.
Training Workbook: HAPPY HCS-1201 Voyager Operation and Maintenance Education Department 1 Training: HAPPY HCS-1201 Voyager Operations & Maintenance (for.
Techniques For Troubleshooting FCC Regenerator Problems.
Thermal Insulation Time allowance: 1 hour Presentation CPD Points: 5 CPD Points Post presentation online quiz: 5 CPD points.
Chapter 15 Fire Control. 15–2 Chapter 15 Lesson Goal After completing this lesson, the student shall be able to attack various types of fires, using effective.
FORCIBLE ENTRY. Modern society is security conscious Private homes Commercial occupancies Vehicles Forcible entry The technique used by fire department.
Objectives Compare and contrast intrusive and extrusive igneous rocks. What are igneous rocks? Describe the composition of magma. Discuss the factors.
Second Law of Thermodynamics No engine, working in a continuous cycle, can take heat from a reservoir at a single temperature and convert that heat completely.
Silicon V2.1 En FROM SILICA TO SILICON WAFER The Silicon Single Crystal and Wafers Manufacturing Version 2.1 En.
PRACTICING FIRE SAFETY. HOW FIRES START Fire is a chemical reaction involving rapid oxidation or burning of fuel. It needs three elements to occur. -Fuel:
PRESENTED BY SATNAM SINGH LECTURER ELECRICAL ENGG. GOVT. POLYTECHNIC COLLEGE MOHALI (KHUNIMAJRA) CONSTRUCTION FEATURES OF DC MACHINES.
29 Reflection and Refraction When waves interact with matter, they can be reflected, transmitted, or a combination of both. Waves that are transmitted.
PLASMA Cutting & Gouging PLASMA Cutting & Gouging ESAB Welding & Cutting Products.
Chapter 14 Fire Streams. 14–2 Chapter 14 Lesson Goal After completing this lesson, the student shall be able to effectively operate a solid stream nozzle,
© 2016 SlidePlayer.com Inc. All rights reserved.